We all love running calculators, because really, the next best thing to actually running is dissecting the details of our last run or planning for our next run. And while there is certainly no dearth of calculators out there to use - good, bad, or ugly that they are - we've come to really like the main calculator on the McMillan Running site (link). What sets it apart from most others is its clean look as well as the wealth of information it provides with just a few clicks of the mouse. Enter your fastest time for a single distance, from 100m to a full marathon, and it'll give you projected finishing times for all those distances, as well as pace estimates for training runs - hard tempo, intervals, recovery, etc. That the longest event one can enter is a marathon may make ultra runners feel a bit snubbed, but they're a smart, hardy lot who can spend some of the time on their 50 mile training runs transposing the numbers to their distances.